1. Field
Embodiments described herein generally relate to methods for making resin or polymer particles in gel form. More particularly, such embodiments relate to methods for making resin or polymer particles in gel form that can be further processed into aerogel, xerogel, and/or cryogel particles.
2. Description of the Related Art
Carbon materials such as carbon aerogels, xerogels, and cryogels have been used in a variety of products to improve properties including, but not limited to, electrical conductivity and energy storage in, for instance, supercapacitor applications. Methods for synthesizing carbon aerogels, xerogels, and cryogels on the laboratory scale are known in the art such as converting polymer gel to carbon materials. One particular composition can include, for example, resorcinol and formaldehyde for producing precursor solutions (e.g., a “monomer component” or “sol,” which is a solution or a colloidal dispersion of particles in a liquid) that can be further processed into a large monolithic polymer gel or “sol-gel.”
The monolithic polymer gels, however, are difficult and expensive to produce and convert into the end product, i.e., aerogel, xerogel, or cryogel. Due to the monolith's large size and low thermal conductivity a significant amount of energy, time, and specialized equipment is required in order to polymerize the monomer component that makes up the monolith structure. Additionally, due to the uneven heating of the monolithic polymer gel as heat is transferred from the outside to the inside thereof, heterogeneous physical differences in the monolithic polymer are formed which can negatively impact the aerogel, xerogel, or cryogel's performance produced therefrom. Furthermore, the large monolithic polymer gel requires physical grinding in order to reduce the monolithic structure into polymer particles in gel form that can then be processed into aerogel, xerogel, or cryogel, which is also labor, capital, and time intensive.
There is a need, therefore, for improved methods for making polymer particles in gel form.